SOUTH BEND, Ind. -- Notre Dame showed the mental toughness against Southern California it was sorely lacking in an embarrassing 35-point loss last season. The No. 14 Fighting Irish rallied for 17 points in the fourth quarter after blowing a two-touchdown lead, and took the lead on Corey Robinson's diving catch with 9:06 left in a 41-31 victory Saturday night. "Our theme all week was the mental toughness that we wanted to exhibit today, it was the one question we wanted to answer," Notre Dame coach Brian Kelly said. "I didn't see anything on the sideline that resembled our guys not believing they were going to come back." EDITOR'S PICKS Notre Dame erupts in fourth quarter to escape with win over rival USC Notre Dame kept its College Football Playoff hopes alive after scoring 17 fourth-quarter points, erasing a seven-point USC lead. C.J. Prosise ran for 143 yards and two touchdowns, and DeShone Kizer threw two scoring passes, the second the 10-yarder to Robinson that made it 38-31. It was the first touchdown of the season for Robinson, who dropped several passes in the loss at Clemson. "I just had to step up when my number was called. Thank God I was able to step up for this team and contribute to our success," Robinson said. The Irish (6-1) also added a touchdown by former USC player Amir Carlisle on a blocked punt. Southern California played for the first time since firing coach Steve Sarkisian on Monday. USC coaches are now 0-7 in their first games against Notre Dame in South Bend with Clay Helton, who took over for Sarkisian, becoming the second straight interim coach to fall. Two years ago it was Ed Orgeron following the firing of Lane Kiffin. The Trojans have had four different coaches against the Irish the past four seasons. "We had great momentum going into the second half. And then, at the end of the day, mistakes hurt us, whether it was penalties, special teams, some missed tackles and some turnovers on offense," Helton said. "You c